ZOMBIE WAR

Rules
Chapter 1
Chapter 2
Chapter 3
Chapter 4
Resources

Chapter 1: Risk factors

Go through the results of some of the noteworthy studies in the field of Z pathogen and answer the questions.

Study 1: Description of the infected population

In the first wave of epidemics, this descriptive study was done. Its aim was to decsribe the basic characteristics of the infected population. Only existing medical records were the source of the data used.

Results:

  • 76% of the infected lived in the infested areas
  • 99% of the infected was bitten by a zombie
  • 20% of the infected were homeless
  • 40% of the infected were smokers

Study 2: Relationship between having a pet and risk of infection in the city population

One of the hypothesis regarding the transfer of the Z pathogen is looking at the Z apthogen as on the antropozoonosis. Researchers established a retrospective cohort study of the population living in the city centre of an European capital, infested by the infection. Infected and not infected citizens of the area were divided to groups based on the pet owned. The results reflecting the risk of getting the disease were processed using logistic regression with adjustment for age and sex.

Results:

  • Dog: OR (odds ratio) 14.6 (95%CI 12.3 - 16.9)
  • Cat: OR 1.5 (95%CI 0.98 - 2.0)
  • Hamster: OR 0.87 (95%CI 0.57 - 1.2)
  • Fish: OR 0.45 (95%CI 0.30 - 0.96)
  • Other animal (snake, turtle…): OR 0.93 (95%CI 0.83 - 1.03)
  • Without a pet: reference category

    • Study 3: Z pathogen as a sexually transmitted disease

    The research group for dermatovenerological disease comes with a revolutionary idea explaining the existence of the Zombie infection in non-bitten people: sexual transmission of Z pathogen. For the quick verification of the idea the researchers organised a case-control study: 1366 infected people were matched with 1366 controls (not-infected). After distribution of a questionnaire asking about a broad range of sexual and relationship habits,the following pattern was found for a relationships status and prefered place for date:

    CasesControls
    Dating in a cinema227194
    Dating in a theatre162368
    Dating in a park89418
    Netflix and chill65664
    Not dating18122
    CasesControls
    Singles91523
    Relationship < 1 year 689107
    Longterm relationship302247
    Marriage284489

    Study 4: Cleaning habits and the risk of infection

    Hygiene as a basis for good health? On the epidemiological conference "News, progress and future outlook in the time of Z", one of the posters presented contained the following plot:

    Obligatory questions:

    1. Which factors are associated with an increased risk of becoming a zombie?
    2. Which factors do not have significant association with the risk of infection?
    3. Which factors are associated with a decreased risk of becoming a zombie?
    4. Do you have in mind any explanation for that? Is there a sign of a confounding factor?
    5. Which from the risk factors is fulfilling at least on of the Bradford-Hill criteria? Why and which criteria? Does it mean, that it is trully the causal factor of the infection?
    6. For which situation is is suitable to use the case-control study design? And for which the cohort study?

    Further questions:

    1. Suggest, how to confirm your hypothesis explaining the results of the observational studies (question 4).
    2. Suggest other possible risk factors, which could have an association (negative or positive) with the risk of infection based on your hypothesis.
    3. Count the RR(risk ratio) and OR (odds ratio) for the risk factor(s) of your choice in Study 4